PLC K120S with K7M-DR20U type is low price PLC with powerful built-in functions, like : PID function, Modbus RTU protocol, High Speed Counter (HSC), Pulse Output. Otherwise, the disadvantage of PLC K120S is could not processing floating data. All analog data will processed using integer format.

Goal target on this case is PLC K120S could set the reference frequency, acceleration, deceleration and monitor current value of output frequency, output current, output voltage and output power from each VSD.

There is a little trick when using modbus function on PLC K120S ladder programming. That is PLC K120S could not send/receive multiple parameter from/to slave device within same time. There will be occuring error communication. Error communication also occuring when PLC K120S request data to multiple slave devices within same time. We attach below the little trick to resolve that issue.

We also develop similar system using PLC Panasonic. Our system using PLC FPX Series from Panasonic as Master device and 2 units VSD iG5A from LS Industrial Systems as Slave device. There is no built-in RS-485 port on PLC FPX Series, so we need add-on communication cassette AFPX-COM3 to perform Modbus RTU communication. On these system, PLC FPX Series also needed similar ladder programming method like on PLC K120S.

We got last confirmation from the end-users that all above design are powerful system. Please fell free to develop your system by using our experiences.

]]> http://www.hydrogen-fc.com/modbus-rturs-485-plc-k120s-to-vsd-altivar-31-ig5a/feed/ 2 http://www.hydrogen-fc.com/pid-close-loop-controller/ http://www.hydrogen-fc.com/pid-close-loop-controller/#comments Sun, 13 Sep 2009 13:05:19 +0000 admin http://www.hydrogen-fc.com/?p=450 PID (Proportional-Integral-Derivative) controller is control loop feedback mechanism that widely used in control system. PID calculating the error value that generated by difference between feedback Process Value (PV) and Set Point (SP) PID. When error value generating, PID controller adjusting output Measurement Value (MV) to minimize error near to zero value.

Let us give some example PID Controller on Booster Pump application like on the left picture. Feedback Process Value (PV) is Actual Pressure (Bar), Set Point (SP) PID is Set Pressure (Bar), and output Measurement Value (MV) is VSD Reference Frequency (Hz).  This is the mechanism. Whenever the difference between PV & SP negative, PID Controller increasing output MV. Otherwise when the difference between PV & SP positive, PID Controller decreasing output MV. How fast the PID Controller could execute error calculation are depend on cycle speed on each controller and type of PID function.  There are several PID function base on control actions, which are P, I, PI, PD. PI function is widely used for Booster Pump application.

This is the PID & Alternate control system on Booster Pump application. There are 1 unit Pressure Transmitter,  1 unit PLC and 2 units Booster Pump that controlled by 1 unit VSD. Because of most VSD have PID Controller, we design the PI controller in the VSD. These are the several case :

• At the first time start PID in VSD with Pump A. VSD adjusting output frequency (Hz) into Pump A so that Actual Pressure (Bar) close to Set Pressure (Bar).
• Case 1 : Pump A couldn’t reach the target of Set Pressure (Bar), then PLC set 50Hz into Pump A and start PID in VSD with Pump B.
• Case 2 : Actual Pressure (Bar) is too high so that VSD set 0Hz into Pump B. This case make PLC to stop Pump B and start PID in VSD with Pump A.
• Case 3 : Actual Pressure (Bar) still on high pressure so that VSD set 0Hz into Pump A. This case make PLC to stop Pump A. That mean booster Pump A and B on the sleep condition.
• Case 4 : Suddenly Actual Pressure (Bar) drop to below Set Pressure (Bar). This case make PLC start PID in VSD with Pump B because of the last running pump before sleep is Pump A. This mechanism important to make sure all pumps have same running hour.

With the PID & Alternate control system, we could just add booster pump without add more VSD  to increase efficiency and capacity on Booster Pump Station. Mostly, Booster Pump Stations are using PID & Alternate control system because it could saving more cost for electrical energy consuption.

All of animation and graphical developed by Wonderware ArchestrA 3.0.

VersaMax40 is one kind of VersaMax Micro Plus Controllers from GE Intelligent Platforms that have more enhanced features like : more memory (for boolean, integer, floating data), real time clock (RTC),  optional port for industrial protocol communication, high speed counter (HSC) up to 4 at 100kHz, pulse width modulation (PWM) up to 4 at 65kHz, motion commands, PID function and subroutines. VersaMax40 limited to 152  maximum physical I/O with up to 4 I/O expansion units.

VersaMax40 have 1 RS-232 and second port option for RS-232/RS-485/USB/Ethernet. Usually, 1 RS-232 port defined as  SNP port mode for PLC programming with Proficy Machine Edition. On This application we will use second port option to add ethernet communication module – IC200UEM001. With this communication module we could self-defined VersaMax40 as Server device that communicate with HMI Ifix5.0 as Client device via Modbus TCP protocol. With ethernet communication module, VersaMax40 could handle up to 8 Clients device simultaneous on Modbus TCP network. Please following GFK-2436B for detail instruction.

Configuring VersaMax40 with Proficy Machine Edition Software

To configure second port option that available on VersaMax40 for Modbus TCP protocol, we should using Proficy Machine Edition software via port 1 RS-232. Port 1 RS-232 on VersaMax40 using RJ45 connector. Below the cable connection between DB9 connector to RJ45 connector.

Configuring IC200UEM001 as Modbus TCP Server

Factory configuration for ethernet communication module – IC200UEM001 is GE Fanuc SRTP function. With these function we could setting the permanent IP address then connect Proficy Machine Edition via crossover ethernet cable to program PLC VersaMax40. To set IC200UEM001 with Modbus TCP Server function please following below  step :

1. Connect IC200UEM001 to computer using crossover ethernet cable.
2. Replace GE Fanuc SRTP with Modbus TCP Server firmware using PumpKIN Utility software. Following GFK2436B for detail instruction.



3. Open Modbus Tester (ex. Modscan) software and testing these below register :
   • Physical input address on VersaMax40 are %I00001 – %I00024 similar with modbus register 100001 – 100024.
   • Physical output address on VersaMax40 are %Q00001 – %Q00016 similar with modbus register 100001 – 100016.
   • Memory (unsigned integer) data on VersaMax40 are %R00001 – etc similar with modbus register 400001  – etc.

Connect HMI Ifix5.0 to PLC VersaMax40

Configuring SCU Ifix5.0 :

1. Click Ifix 5.0 shortcut.
2. Click SCU (System Configuration Utility).
3. Click Configure.
4. Select Enable SCADA support.
5. Find I/O Driver Name : MBE Modbus Ethernet and click Add.
6. Click Configure the I/O Driver.
7. Click Connect to MBE I/O driver.
8. Save SCU configuration.

Configuring MBE I/O driver Ifix5.0 :

1. Click Add New Ethernet Port channel and enable it.
2. Click Add New Device and enable it. Then fill the form for IP address, maximum block, timeout, addressing mode and bit mode swapping register.
3. Click Add New Block and enable it. Then spit each type modbus register.  These is an example of MBE I/O driver configuration.
4. Save MBE I/O driver configuration and close all Ifix5.0 application.

Configuring Database Manager Ifix5.0 :

1. Click Ifix5.0 shorcut.
2. Click Application.
3. Click Database Manager.
4. Add tagname name, tagname type, I/O driver, I/O addresss.
5. Save all configuration on Database Manager.

After that, create simple animation or symbol in HMI Ifix5.0 that connected to I/O tagname. All I/O tagname are defined in Database Manager.

For the information, Ifix5.0 support with Visual Basic syntax. It means  that HMI Ifix5.o support for customable HMI programming (ex.  programming database to Access, MySQL, SQL Server, etc). With this capability, you could self-programming to create HMI based on your application/project.

• Ladder Diagram (LD)
• Function Block Diagram (FBD)
• Structured Text (ST)
• Instruction List (IL)
• Sequential Function Chart (SFC)

With the IEC-61131-3 standard package, ADAM-5510KW/TCP support for comprehensive controling distribution, processing data and have more capability than old PLC function. Moreover, ADAM-5510KW/TCP also support with modbus TCP (Server/Client) and RTU (Master/Slave) protocol. These standard open protocol enable ADAM-5510KT/TCP to communicate with other device.

For this chapter, I will show you how to move the analog data from AI module into modbus register so it could reading online by HMI5104T via modbus TCP protocol. There are several hardware/software that need to provided :

1. PAC ADAM-5510KW/TCP
2. HMI Touchscreen Maple HMI5104T
3. Ethernet Switch Hub
4. 2 Straight ethernet cables
5. 1 RS-232 cable (female to female DB9 connector) or Serial to USB converter
6. Software KW Multiprog for ADAM-5510KW/TCP
7. Software EasyBuilder5000 v1.31 for Maple HMI5104T
8. PC or Laptop

Before you could perform PAC programming via KW-Multiprog, please configure these DIP switch. There are up to 8 DIP switch, where DIP 1 to 5 used for setting the device ID of ADAM-5510KW/TCP and DIP 6 to 8 used for setting the protocol communication in COM1 and COM2. On this chapter I will configure device ID = 1 and COM1 = RS-232 (baudrate 19200) for Multiprog Protocol. So only DIP 1 change to ON position. After that I insert the AI module into ADAM-5510KW/TCP PAC I/O slot and power on ADAM-5510KW/TCP with 24VDC power supply. Then connect COM1 ADAM-5510KW/TCP into PC or Laptop to start KW-Multiprog programming.

Click the icon of KW-Multiprog on Start Menu to create New Project base on ADAM5000. After that please select the active serial COM on Resource IPC_30. Don’t forget to configure baudrate, stopbits, databits, parity, timeout similar with you physical COM PC or Laptop. Because All of I/O module that inserting into ADAM-5510KW/TCP slot board should defining in I/O configuration, so that you have to define the AI module in I/O Configuration. On I/O configuration, you should also set the IP address (ex: 192.168.1.1) of ADAM-5510KW/TCP to perform the next modbus TCP communication.

After you have successful install add on ADAM5000 library, you will have ADAM5K_AI function block. This function block using to move analog data from AI Module into modbus register. This is the simple configuration of ADAM5K_AI :

• EN : BOOL#1
• Slot : INT#0 (depend on your AI module placed)
• CHx : CH0_AIx, where x = 0, 1, 2, …, 7 and CH0_AI is UINT data type with I/O address start from %MW3.0

After you have finish configure ADAM5K_AI, build your own project by pressing F9 to ensure there is no error in your project. To download into ADAM-5510KW/TCP click Online -> Project Control -> Download -> Download -> Cold. To see you project in online view click Online -> Debug (F10), then you will see the real analog value of AI module in Unsigned Integer (0 – 65535) representation. When you download your project into ADAM-5510KW/TCP, the IP address that have you set also download on there. It means that you could use UTP ethernet cable to perform the modbus TCP and Multiprog communication. Until this step, ADAM-5510KW/TCP success configurated and we will go to configure HMI5104T using EasyBuilder5000 v1.31.

Power on HMI5014T with 24VDC to set IP address (ex: 192.168.1.2) manually. Then click EasyBuilder5000 icon on the Start Menu, then create New HMI Project (Ctrl+N) with model HMI5104x (640 x 480). On the EasyBuilder5000 v1.31 there are several model of Maple System touchscreen, as you can see on left.

On the System Parameter Setting, you should define the protocol/driver communication which will used between HMI5014T and ADAM-5510KW/TCP. For this chapter I choose modbus TCP protocol which these configuration :

• Radio check box : PLC
• PLC type : Modbus TC/IP Master
• PLC I/F : Ethernet
• PLC default station no : 1 (depend on modbus address of ADAM-5510KW/TCP)
• Setting IP Address : 192.168.1.1 (depend on IP set of ADAm-5510KW/TCP)
• Port no : 502

After you have create new HMI workspace, insert Numerical Display symbol and you will see a new popup window. On the popup window, you could configure the modbus function and modbus register, custom the graphical and text display or animation. The general configuration for this chapter are :

• Device type : 4x (Read/Write Holding Register)
• Address : 2001 to 2008
• Data format : 16-bit Unsigned
• Left of decimal Pt: 5

Please insert 8 Numerical Display symbols on the EasyBuilder5000 workspace, where each symbol used for each modbus register address. To verifying your project, click Tools -> Compile. To download your project to HMI5014T, click Tools -> Download. Before you download, you should have know the IP address, password of HMI5014T and connect your PC or Laptop with UTP ethernet cable. For this chapter the IP address : 192.168.1.2 and default password : 111111. After that, replace RJ45 port from your PC/Laptop into ADAM-5510KW/TCP. You will see the actual analog data of AI module in HMI5014T Touchscreen.

All of configuration that I have explain is base on my experiences. So that I could ensure you the configuration could perform the modbus TCP communication between ADAM-5510KW/TCP and HMI5014T Touchscreen. But if you have any questions or technical advice, please contact me immediately.